Numerical Simulation Analysis of Side Aerodynamic Force of Car in the Course of Passing Heavy Goods Vehicle (HGV) *

In the course of study on aerodynamic change and its effect on steering stability and controllability of automobiles in passing, because there are multi - interaction streams, it is difficult to use traditional methods, such as wind tunnel test and road experiment methods. If the process of passing a vehicle is divided many time segments, and then the segments are simulated with CFD (Computational Fluid Dynamics) method, then the approximate computational results about external flow field will be gotten. Based on the idea, numerical simulation analysis of side force coefficient of car in the course of passing Heavy Goods Vehicle ( HGV ) and preliminary discussion of aerodynamic characteristics of correlative situations for car are presented in the paper, by means of dividing the passing process to many time segments and then simulating external flow field of every time segment through solving three-dimensional, steady and uncompressible N-S equations with Finite Volume Method, this avoids the use of moving mesh, which takes a large calculation resource and CPU processing time in calculating. Finally, the result of the side force coefficient of car is presented and coincident well with the experimental data, which shows creditability of numerical simulation methods presented in the paper.